---
license: apache-2.0
task_categories:
  - text-generation
language:
  - en
tags:
  - web-crawl
  - pretraining
  - nlp
  - text-corpus
pretty_name: Web Crawl 2026
size_categories:
  - 10B<n<100B
---

# Web Crawl 2026

A large-scale web crawl dataset for language model pretraining, collected by the OpenTransformer project.

## Dataset Description

This dataset contains text extracted from web pages crawled directly from the internet using custom high-throughput crawlers. All data is freshly scraped.

### Data Format

Each record is a JSON line (gzipped) with fields:
- text: extracted text content (200-200,000 chars)
- url: source URL
- domain: source domain
- timestamp: crawl timestamp (ISO 8601)
- source: crawler identifier (crawl_rust_v1, crawl_go_v1, crawl_v5)

### Collection Methods

Three crawlers run in parallel on a Vast.ai GPU box (Titan Xp, $0.06/hr):

| Crawler | Language | Throughput | 1.2GB Chunk Time | Architecture |
|---------|----------|------------|-------------------|-------------|
| crawl_rust | Rust | 150-300 docs/s | 5-6 min | 500 async workers, tokio |
| crawl_go | Go | 11 docs/s | ~2 hrs | 150 goroutines |
| crawl_v5.py | Python | 0.8 docs/s | ~25 hrs | 20 async workers |

The Rust crawler is 27x faster than Go and 375x faster than Python.

### Rust Crawler Architecture

Source code: crawler/rust/

Key design decisions:
- 500 concurrent async workers via tokio + semaphore-based backpressure
- Background queue refiller: seed fetching runs in a separate task, never blocks crawling
- Pre-generated seed file: 593K URLs from Common Crawl index (12 crawl versions x 20 TLD patterns)
- Link discovery: extracts up to 50 links per crawled page, shuffled for domain diversity
- Content dedup: MD5 hash of first 500 chars, stored in DashMap (lock-free concurrent hashmap)
- Domain throttling: max 1000 pages per domain to ensure diversity
- Streaming gzip: writes compressed JSONL chunks (~1.2GB raw -> ~350MB compressed)
- Auto-upload: each completed chunk is uploaded to HuggingFace Hub

Seed sources:
1. Common Crawl URL index (CC-MAIN-2024-10 through CC-MAIN-2025-08)
2. Wikipedia random articles API (20K articles)
3. Sitemaps from 34 major sites (Reuters, BBC, Nature, StackOverflow, etc.)
4. Hacker News top/new/best stories

Performance on Titan Xp box ($0.06/hr):
- Phase 1: 562K seeds loaded in 28 seconds
- Phase 2: 150-300 docs/s sustained throughput
- ~1.2GB chunk every 5-6 minutes
- ~12-15 GB/hour of raw crawled text
- Cost: ~$0.004 per GB of crawled text

### Building and Running

Install Rust, then:

    cd crawler/rust
    cargo build --release
    ulimit -n 65536
    ./target/release/crawl_rust > crawl.log 2>&1

### Quality Filtering

- HTML text extraction via scraper crate (article/main/body selectors)
- Minimum 200 chars, maximum 200K chars
- Content-type filtering (only text/html)
- URL filtering: blocks social media, login pages, media files, admin pages
- Deduplication via MD5 content hash

## Intended Use

Pretraining data for the AGILLM-3 language model (698M params, joint AR+SAT architecture).

## License

Apache 2.0